Grinding and polishing device



March 3, 1936. A. KNAFF GRINDING AND POLISHING DEVICE Filed Jan. 23, 1933 2 Sheets-Sheet l March 3, 1936.

A. KQAFF 2,033,03

,GRINDING AND POLISHING DEVICE Filed Jan. 25, 1953 2 Sheets-Sheet 2 1 34W Elf 6 INVeNTORL,

y man/1M I Patented Mar. 3, 1936 UNITE STATS Application January 23, 1933, Serial No. 653,154 In Germany January 23, 1932 4 Claims.

'The object .of the present invention is a device relating to grinding and polishing of flat surfaces, more especially in the manufacture of plate glass.

.In accordance with this method the grinding and polishing tools machine the surfaces to be ground and polished under a very low pressure-contrary to pressures hitherto customaryfurther, the grinding and polishing tools run at a high relative speed between tool and workpiece-contrary to speeds customary at present. By this same method afore described ways of operating may both be applied in conjunction and simultaneously.

The grinding and polishing device which forms the object of the present invention comprises a system of rotary grinding and polishing elements respectively suspended, for the purpose of dealing with the work-piece, in a suitable manner, for example from stationary girders. A certain number of these tools, six for example, suitably grouped in a circle, are, either in their totality or singly, supported in bearings of vertical direction in which they rotate carefully balanced by means of counterweights or other suitable means, so as to permit the working pressure to be adjusted within the finest limits.

Each single tool as well as the whole system of tools rotate around their vertical axes, each single tool very rapidly, the whole system at a lower speed, according to the special requirements of the work-piece to be dealt with.

Special advantage ofiers the independent driving of each single grinding tool by means of an electro-motor with vertical shaft in which case the grinding tool may be mounted on the lower portion of this hollow shaft which is connected with the armature of the motor. This hollow shaft is suspended with its upper portion from a ring supported by ball bearings, the ring in its turn being suspended from a balanced lever carrying counterweights. Through said hollow shaft grinding substance may be admitted to the grinding tool and the place to be ground.

The supporting element of the device around which are fixed the rotating tools with their driving devices etc. is supported, at a portion above these parts, in a sleeve bearing of larger diameter within the fixed frame of the device and rotates within this sleeve bearing, preferably driven by means of a worm wheel, comparatively more slowly around the vertical axis. The whole supporting element is at the same time arranged vertically slideable within the sleeve bearing and suspended with its upper extension from a bearing ring which is supported. by a balancing lever with counterweight.

In the accompanying drawings is:-

Fig. 1, a side view of the device with portions shown in section.

Fig. 2, a section through a portion of the device below the sleeve bearing showing the top portion of the tools or their driving and supporting organs respectively.

The stationary girders I and 2 carry the supporting frame 3 of the device. On said frame are arranged the lower sleeve bearing 4 and an upper sleeve bearing 5. Within these sleeve bearings 4 and 5 rotates and slides the supporting element 6 which carries the tools and their driving devices. Said supporting element is driven by a worm wheel 1 which is driven in its turn by worm 8. A ring I ll, fitted with ball bearing 9, is mounted to that end of said supporting element which protrudes from sleeve bearing 5. Said ring III is suspended by means of suspension device II from a balancing lever I2. The adjustable counterweight (not shown in the drawing) is fitted to the left end of said balancing lever which is articulated on the fixed member I3.

Worm wheel I which drives the supporting element is fixed to a cylindrical bush I4 connected slideable but not rotatory to the long journal of supporting element Ii. Slide rings I6 for the electric current admission to the motors may be arranged at the upper end I5 of the rotatory bush I4.

Fig. 2 of the drawings shows clearly the arrangement of the various tools with their driving and suspension devices around the lower cylindrical portion of the supporting element.

In the case of electrically driven tools motor housings H are fixed immediately to the supporting element 6 by means of bolts and lashes.

The vertical shaft I8 of each motor carries at its lower end a grinding or polishing tool I9 respectively, whilst the upper end of said shaft is suspended from balancing lever 22 by means of ball race 2!] and suspension device 2|. Said balancing lever is weighted at its outer free end by changeable weights 23.

Grinding substance may be admitted through hollow shafts I8. To prevent the danger of corrosion by grinding substance coming into direct contact with said shafts it is advisable to provide tube 24 made from special non-rusting material which is widened at its upper end to serve as funnel. Grinding substance is admitted from above through pipes 25. These pipes run through the hollow journal of supporting element 6 being connected with a distributing chamber 26 arranged at the uppermost portion of said supporting element. The distributing chamber is fed with grinding substance from above through a pipe of suitable diameter.

In the case of the device being constructed with non-sliding grinding shafts instead of ver-' tically slideable shafts the suspension devices and counterweights are omitted. In that case all tools can only be moved upwards and downwards conjointly with the supporting element or adjusted as to pressure effect. The possibility, however, of adjusting and balancing each single tool independently from the others ensures a much more minute regulating of the pressure.

The various details of the device may, of course, deviate more or less from the example shown in the accompanying drawings without influence on the nature of the present invention.

I claim:

1. A device for grinding and polishing flat surfaces, more especially in the manufacture of plate glass including a frame mounted in a fixed position above the work, a support in the form of a. hollow tubular member mounted for rotatable and vertically slidable movement in the frame, a plurality of operating tools on the support, means for rotating the support with the tools thereon, means for adjusting the vertical position of the support as well as the tools, means for rotating the tools independently of the means for rotating the support including a stator, a rotor including a hollow shaft forming the spindle of the tool and vertically slidable relative to the stator, and means for individually adjusting the tools including a series of variable counterbalanced levers operably mounted on the support and operably connected to the upper ends of the shafts.

' '2. A device as claimed in claim 1, wherein a the rotor operates at any height within the stator 20 and can thereby be adjusted at any desired height.

4. A device as claimed in claim 1, wherein heads are fixed on the lower ends of the hollow shafts and together with the shafts form tools of relatively small weight to ensure of an easy movement of the tools in a vertical direction.

ALBERT KNAFF. 

